Two-year follow-up of a postpartum weight loss intervention: Results from a randomized controlled trial

We recently reported that a 12-week diet intervention among postpartum women produced a weight loss of 12% after 1year, compared to 5% in controls. Here, we present 2-year results after 1year of unsupervised follow-up. In total, 110 women with a self-reported body mass index of 27kg/m(2) at 6-15-week postpartum were randomized to diet group (D-group) or control group (C-group). D-group received a 12-week diet intervention by a dietitian followed by monthly e-mails up to the 1-year follow-up. C-group received a brochure on healthy eating. No contact was provided from 1 to 2years to either group. Eighty-nine women (81%) completed the 2-year follow-up. Median (1st; 3rd quartile) weight change from 0 to 2years was -6.9 (-11.0; -2.2) kg in D-group and -4.3 (-8.7; -0.2) kg in C-group. There was no group by time interaction at 2years (p=.082); however, when women with a new pregnancy between 1 and 2years were excluded, the interaction became significant (-8.2 vs. -4.6kg, p=.038). From 1 to 2years, women in D- and C-group gained 2.5 +/- 5.0kg and 1.1 +/- 4.4kg, respectively (p=.186). Women who gained weight from 1 to 2years reported a decrease in self-weighing frequency compared to women who maintained or lost weight (p=.008). Both groups achieved clinically relevant 2-year weight loss, but the significant between-group-difference observed at 1year was not maintained at 2years in the main analysis. However, when women with a new pregnancy between 1 and 2years were excluded, a significant weight loss effect was observed also at 2years.